As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN - FLIGHT 5888, THE CREW REPORTED AN ENGINE 2 FIRE DET FAIL MESSAGE ON EICAS DURING CLIMB. THE AIRCRAFT RETURNED TO DEN WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NUMBER TWO ENGINE HARNESS, OPERATIONALLY TESTED WITH NO DEFECTS, AND THE AIRCRAFT WAS APPROVED FOR RETURN TO SERVICE.